Electric motor with permanent-magnet excitation
US5418414A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 28, 1994 |
| Grant date | May 23, 1995 |
| Priority date | — |
| Expiry date | Mar 28, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K21/22
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The invention relates to an electric motor with permanent-magnet excitation, particularly inside-rotor and outside-rotor motors, comprising motor sections (10, 20) which are movable relative to one another, of which the first motor section (10) forms a multi-pole excitation field in an air gap (1) by means of permanent magnets (11) and of which the second motor section (20) is a soft-iron yoke (21) having pole teeth (22) which project towards the air gap (1) and which carry excitation coils (23). The motor combines the following characteristic features: PA1 a) the pole teeth (22) which project from the soft-iron yoke (21) of the second motor section (20) toward the air gap (1) are free from recesses at the location of the air gap (1), PA1 b) in the proximity of the air gap (1) the smallest distance between adjacent pole teeth (22) which project from the soft-iron yoke (21) of the second motor section (20) toward the air gap (1) is as small as is allowed by production, PA1 c) the transitional areas between areas with different directions of magnetisation of the permanent magnet (11) of the first motor section (10) extend parallel to the motor shaft, and PA1 d) the permanent magnet (…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.